/*
 * Copyright (C) 2012 Freek van Tienen
 *
 * This file is part of paparazzi.
 *
 * paparazzi is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * paparazzi is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with paparazzi; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */

/**
 * @file gps_sirf.h
 * @brief Sirf protocol specific code
 *
 */

#ifndef GPS_SIRF_H
#define GPS_SIRF_H

#include "std.h"

#define GPS_NB_CHANNELS 16
#define SIRF_MAXLEN 255

//Read states
#define UNINIT	0
#define GOT_A0	1
#define GOT_A2	2
#define GOT_B0	3

struct GpsSirf {
  bool_t msg_available;
  bool_t pos_available;
  char msg_buf[SIRF_MAXLEN];  ///< buffer for storing one nmea-line
  int msg_len;
  int read_state;
};

extern struct GpsSirf gps_sirf;

//Invert bytes
#define Invert2Bytes(x) ((x>>8) | (x<<8))
#define Invert4Bytes(x) ((x>>24) | ((x<<8) & 0x00FF0000) | ((x>>8) & 0x0000FF00) | (x<<24))

/** Message ID 2 from GPS. Total payload length should be 41 bytes. */
struct sirf_msg_2 {
  uint8_t msg_id; 		///< hex value 0x02 ( = decimal 2)
  int32_t x_pos; 		///< x-position in m
  int32_t y_pos; 		///< y-position in m
  int32_t z_pos; 		///< z-position in m
  int16_t vx; 			///< x-velocity * 8 in m/s
  int16_t vy; 			///< y-velocity * 8 in m/s
  int16_t vz; 			///< z-velocity * 8 in m/s
  uint8_t mode1;
  uint8_t hdop; 		///< horizontal dilution of precision *5 (0.2 precision)
  uint8_t mode2;
  uint16_t week;
  uint32_t tow; 	    ///< time of week in seconds * 10^2
  uint8_t num_sat; 		///< Number of satellites in fix
  uint8_t ch1prn; 		///< pseudo-random noise, 12 channels
  uint8_t ch2prn;
  uint8_t ch3prn;
  uint8_t ch4prn;
  uint8_t ch5prn;
  uint8_t ch6prn;
  uint8_t ch7prn;
  uint8_t ch8prn;
  uint8_t ch9prn;
  uint8_t ch10prn;
  uint8_t ch11prn;
  uint8_t ch12prn;
} __attribute__ ((packed));


/** Message ID 41 from GPS. Total payload length should be 91 bytes. */
struct sirf_msg_41 {
  uint8_t msg_id; 			///< hex value 0x29 (= decimal 41)
  uint16_t nav_valid; 		///< if equal to 0x0000, then navigation solution is valid
  uint16_t nav_type;
  uint16_t extended_week_number;
  uint32_t tow; 			///< time of week  in seconds *10^3]
  uint16_t year;
  uint8_t month;
  uint8_t day;
  uint8_t hour;
  uint8_t minute;
  uint16_t second;
  uint32_t sat_id; 			///< satellites used in solution. Each satellite corresponds with a bit, e.g. bit 1 ON = SV 1 is used in solution
  int32_t latitude; 		///< in degrees (+= North) *10^7
  int32_t longitude; 		///< in degrees (+= East) *10*7
  int32_t alt_ellipsoid; 	///< in meters *10^2
  int32_t alt_msl; 			///< in meters *10^2
  int8_t map_datum;
  uint16_t sog; 			///< speed over ground, in m/s * 10^2
  uint16_t cog; 			///< course over ground, in degrees clockwise from true north * 10^2
  int16_t mag_var; 			///< not implemented
  int16_t climb_rate;		///< in m/s * 10^2
  int16_t heading_rate; 	///< in deg/s * 10^2
  uint32_t ehpe; 			///< estimated horizontal position error, in meters * 10^2
  uint32_t evpe; 			///< estimated vertical position error, in meters * 10^2
  uint32_t ete; 			///< estimated time error, in seconds * 10^2
  uint16_t ehve; 			///< estimated horizontal velocity error in m/s * 10^2
  int32_t clock_bias; 		///< in m * 10^2
  uint32_t clock_bias_err; 	///< in m * 10^2
  int32_t clock_drift; 		///< in m/s * 10^2
  uint32_t clock_drift_err; ///< in m/s * 10^2
  uint32_t distance; 		///< Distance traveled since reset in m
  uint16_t distance_err; 	///< in meters
  uint16_t heading_err; 	///< in degrees * 10^2
  uint8_t num_sat; 			///< Number of satellites used for solution
  uint8_t hdop; 			///< Horizontal dilution of precision x 5 (0.2 precision)
  uint8_t add_info; 		///< Additional mode info
} __attribute__ ((packed));

/*
 * This part is used by the autopilot to read data from a uart
 */
#define __GpsLink(dev, _x) dev##_x
#define _GpsLink(dev, _x)  __GpsLink(dev, _x)
#define GpsLink(_x) _GpsLink(GPS_LINK, _x)

#define GpsBuffer() GpsLink(ChAvailable())

#define GpsEvent(_sol_available_callback) {             \
    if (GpsBuffer()) {                                  \
      ReadGpsBuffer();                                  \
    }                                                   \
    if (gps_sirf.msg_available) {                       \
      gps.last_msg_ticks = sys_time.nb_sec_rem;         \
      gps.last_msg_time = sys_time.nb_sec;              \
      sirf_parse_msg();                                 \
      if (gps_sirf.pos_available) {                     \
        if (gps.fix == GPS_FIX_3D) {                    \
          gps.last_3dfix_ticks = sys_time.nb_sec_rem;   \
          gps.last_3dfix_time = sys_time.nb_sec;        \
        }                                               \
        _sol_available_callback();                      \
      }                                                 \
      gps_sirf.msg_available = FALSE;                   \
    }                                                   \
  }

#define ReadGpsBuffer() {                                   \
    while (GpsLink(ChAvailable())&&!gps_sirf.msg_available)	\
      sirf_parse_char(GpsLink(Getch()));                    \
  }

extern void sirf_parse_char(uint8_t c);
extern void sirf_parse_msg(void);

#endif /* GPS_SIRF_H */
